Key for a lock



FIG. 1 is a top, front, and right side perspective view of a key for a lock showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a front elevational view thereof; and,

FIG. 7 is a top plan view thereof. 

The ornamental design for a key for a lock, as shown and described. 